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(NoMndeL) I J. S. POTTER 82; D. J. GARTWRIGHT. CIRCUIT BREAKER AND CLOSER.

No. 443,404. Patented Dec. 23, 1890.

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W 1. 1 F 6 I. I W a a i i" M I UNITED STATES PATENT OFFICE;

:JOIIN S. POTTER, OF NEWTON, AND DAVID J. CARTXVRIGHT, OF BOSTON,

MASSACHUSETTS; SAID CARTlVRIGHT ASSIGNOR TO SAID POTTER.

CIRCUIT BREAKER AND CLOSER.

SPECIFICATION forming part of Letters Patent No. 443,404, dated December 23, 1890.

Application filed August 16, 1890. Serial No. 362.188. (No model.)

To all whom it may concern:

Be it known that we, JOHN S. POTTER, a citizen of the United States, and a resident of Newton, in the county of Midd leseX and State of Massachusetts, and DAVID J. CARTWRIGHT, a citizen of the United States, and a resident of Boston, in the county of Suffolk and'State of Massachusetts, have jointlyinvented new and useful Improvements in Circuit Breakers and Closers, of which the following, taken in connection with the accompanying drawings, is a specification.

This invention relates to improvements in circuit breakers and closers particularly adapted for use on key-sockets for incandescent electric lamps; and it is carried out as follows, reference being had to the accompanying drawings, wherein Figure 1 represents a side elevation of a key-socket made in accordance with our invention, and showing the circuit as being closed. Fig. 2 represents a central longitudinal section on the line X X, shown in Fig. 1; and Fig. 3 represents a side view of the circuit breaker and closer, showing the comm utator in the act of breaking the circuit.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

In the drawings, A represents the metal cap of akey-socket, having screw-threaded nut A made in one piece with or secured to it, as usual. To the lower end of the cap A is secured in a suitable manner the ordinary hardrubber base-plate A".

B is the central metal post, the upper end of which is screwed to the hard-rubber baseplate A, and having its lower screw-threaded end B screwed through the hard-rubber disk 0, as is usual in devices of this kind.

To the lower projecting screw-threaded end of the part B is to be attached the incandescent lamp, as usual, the latter being, however, not represented in the drawings, as it forms no part of our present invention.

To the hard-rubber disks A and C are secured, as usual, the respective metallic contact-springs a and c, the former being electrically connected to the binder-post a and line-wire, as usual. The lower contact-spring c is to be electrically connected to one end of the lamp-wire, the other end being supposed to be electrically connected to the central metallic post B, as is usual in devices of this kind. I) is a binder-screw, as usual, on the post B, to which the line-wire is to be attached, as usual.

A lateral perforation is made through the metal post B, in which is inserted and secured a sleeve D, made of hard rubber or similar insulating material, and in said sleeve is loosely journaled the metal key-spindle E, having a key or handle E in its forward end, as shown in Fig. 2.

To the rear end of the key-spindle E is loosely pivoted the four-sided commutatorblock F, preferably made of porcelain or equivalent insulating material, which block is actuated by a projection 6 working against the sides of a transverse groove f in the outer end of the commutator-block F, as usual.

On two opposite sides of the commutatorblock F are secured metal contact-plates g g, connected on the back of the block F by means of a centrally-perforated commutatorplate G, through which passes the rear end of the insulating-sleeve D, by which arrangement the metal key-spindle E is kept insulated from the plate G, its contact-plates g g and contact-springs ac, thus preventing the electric current when closed through said springs from passing to the key-spindle and its key, and thus permitting the use of a metallic key without the liability of communicating a dangerous shock to the party operating the lamp to which the key-socketis attached. The contact-plates g gare each made somewhat shorter than the width of the commutator-block F, and the latter has its corners rounded off or cam-shaped, as shown at f f f f in Figs. 1 and 3, which rounded or cam-shaped corners serve two purposes, namelyfirst, to aid in closing the circuit when the commutatorblock is turned in a direction opposite to that shown by arrow in Fig. 3, during which operation said curved cornersurfaces act as cams against the contact-springs just a little in advance of closing the circuit, and, secondly, for the purpose of prolonging the contact and preventing the maintaining of an are in breaking the circuit when the commutator-block F is turned in the direction of arrow shown in Fig. 3, during which operation the nah ed faces of the block F are brought in contact with the respective contact-springs a c the very moment the contact-plates g g are liberated from contact with the metal springs a c.

Having thus fully described the nature, construction, and operation of our invention, we wish to secure by Letters Patent, and claim 1. In an electric-circuit breaker and closer, the combination of a metallic post 13, an illsulating sleeve D, extending through the post, a metallic hey-spindle E, journaled in the insulating-sleeve and extending therefrom, an insulating commutator-block F, loosely journaled on the projecting; end of the key-spindle and abutting directly against one end of the insulating-sleeve, and the commutatorplate G, mounted on the commutator-block and arranged over the insulating-sleeve to prevent contact with the metallic key-spindle and provided with contactplates to be brought in contact with the circuit-closing springs, substantially as described.

2. In an electric-circuit closer and breaker, the combination, with the opposite circuitclosing springs a and a and a metallic post B, of an insulating-sleeve D, extending through the post, a metallic key-spindle E, journaled in the insulating-sleeve and extending there-' from, an insulating commutator-block F, provided with cam-shaped corners f and loosely journaled on the projecting end of the keyspindle to abut directly against the end of the insulating-sleeve, and the commutatorplatc G, mountedon the commutator-block and arranged over the insulating-sleeve to prevent contact with the metallic key-spindle, and provided with contact-plates to be brought in contact with the circuit-closing springs, substantially as described.

In testimony whereof we have signed our names to this specification, in the presence of two subscribing witnesses, on this 5th day of August, A. D. 1890.

JOHN S. POT Eli. DAVID J. CAR'IWRIGll'l.

\Yitnesses:

ALBAN ANDRE-N, ALICE A. Pcnrcixs. 

